Telephone repeater apparatus.



N. G. WARTH.

TELEPHONE REPEATER APPARATUS. APPLICATION FILED DBO. 20.1007.

Patented Oct. 26, 1909.

w 3% m g QP PP n I1 avwc m fo'e NATHANIEL G. WART H 9 m mN 'NI ED STATES PATENT OFFICE.

NATHANIEL G. wan'rn, or GALLIPOLIS, 01110.

TELEPHONE REPEATER APPARATUS,

Specification of Letters Patent.

Application filed December 20, 1907. Serial No. 407,314.

T 0 all whom it may concern:

Be it known that I, NATIrANIE G. WARTH, a citizen of the United States, residing at Gallipolis, in the county of Gallia and State of Ohio, have invented a certain new and useful Improvement in'Telephone Repeater Apparatus, of which the following is a specificatlon.

This invention relates to an improved telephone-current repeater apparatus for location or connection at an intermediate point or series of such points in a telephone. main line circuit. 1

The invention is directed more particularly to an instrument adaptableto service of various conditions, as, for example: (1) in reciprocally operating repeater systems of the type described in United States Patent No. 845,282, issued to me February 26, 1907, and also in Patent No. 864,713, of. the

same country, issued to me August 27, 1907, in which but one repeater instrument is necessary and the retransmission from it is divided, being bi-directional or impressed upon both line circuits simultaneously; (2) in reciprocally operating systems of the-type described in patent of the United States No.

850,079, issued to meApril 9, 1907, and in a modification of the same general type, of system for which Letters Patent -of\the United States was applied for by me on July 12,- 1907, s. No. 383,883, and in which two repeater instruments arenecessary for reciprocal epeating and the retransmission from the is uni-directional or' impressed uponthe l'ines progressively only; and (.3) in a system for w i'ch I have applied for Letters Patent of the United States on April 22, 1907, S. No. 369,524, in which system two repeater-instruments are also necessary for or service referred to, by utilizing it in single or in double units according to the system,

agplicatio'n for patent filed July 12,

and by changing the windings or connections thereto to meet the particular or respective use, according to the requirements Patented Oct. 26, 1909.

of the inventions shown: in the patents and applications to which reference has been made. s

The chief object of the presentinvention isto produce an instrument of improved form and of greater sensitiveness and efficiency, thus securing more positive and'reliable operation, as will. be particularly eX-,

plained herein and delineated in the drawmgs. 1

The repeater,.as herein shown, comprises two principal elements, namely, a magnetically sensitized electro-magnetic receiver and a variableresistance transmitter, arranged or assembled in repeater-relation.

The invention consists in the form and arrangement of detail members and parts entering into the organization and association of the principal elements. The particular form and arrangement of the several arts formingthis particular embodiment o the invention, asset forth here-- in, may be varied without departing from the scope and spirit of the invention,

The dimensions of the several members, parts and adjustments maybe varied, it sufiicing to state that the entire apparatus,

particularly as to themoving and mobile parts and members, as will be readily'understood by those skilled in the Part, should be of substantial yet delicate construction, so as to secure maximum possible results and .efliciency with a working. force-so minuteand transitory or fugitive as a telephone current enfeebled or attenuated bylong or difficult transmission. M t i In the accompanying drawings-Figure 1 is a front elevation-or plan view, according to its position in use, partially in section, of

my repeater instrument comprising a receiverand a transmitter assembled in re peater relation; Fig. 2 1s a new in side elevation, partially in section, of the repeater instrument; Fig. 3 isan end view, also partially insection, of the same instrument. This viewv represents the top or transmitter end of'the apparatus and is particularly directed to the support for the transmitter; 105' Fig. 4 is an end view of the receiver proper,

representing'the same viewed from the transmit-ter end of the instrument and showing the mounting and arrangement of the pole pieces and magnet spools and also the location of the wedge-shaped armature, which is indicated in dotted outline in front of the poles; Fig. 5 represents an adjustable fur- 7 represents one of the soft iron cores and V pole pieces of the receiver with its beveled polar surface, which is adapted to use with the wedge-or V-formed armature; Fig. 8 illustrates the wedge or V-formed armature, viewed endwise, and the opposed beveled poles, with lines drawn to indicate the magnetic flux space and the extended space for the armature movement.

In Fig. l the receiver T and transmitter M are preferably arranged in vertical position with the transmitter above the receiver. From the construction shown it will be obvious that the instrument may be placed in any position, but the preferred position is with the diaphragm horizontally disposed, thereby permitting the carbon granules to arrange themselves loosely and practically uniformly as to density throughout the mass. This position avoids the tendency on the part 'of the granules of carbon to pack or become compressed, which is frequently the case in the instruments having a vertically positioned diaphragm and carbon chamber. A packed transmitter element fails to respond to minor or delicate impulses on its diaphragm, and such a state of imperfection in a repeater renders it impracticable, or at least unreliable, and is especially to be avoided. The conditions conducing to the packing also restrain the diaphragm or vibratin member of the transmitter from free an proper movement. These conditions. are theeffect of gravity and the pocket form of the lower 'side'of the carbon chamber, a combination preventing a full and free movement of the carbon granules when the diaphragm'presses inward or moves outward. As in the view, with the diaphragm D arranged horizontally, the granules lie loosely and evenly distributed on its upper surface and are notforced into a confining ocket which tends-to render the proper y mobile partsimmovable. In' the vertical arrangement of the repeater the movements of the diaphragm agitate almost the entire body of the freely movable granules. The granules not particlpating in the vibrations lie around the square lower corner of the carbon granule chamber A and are utilized to reserve a constant closed circuit, necessari y of comparatively high resistance, for the transmitter when the front or principal carbon electrode E is vibrated vigorv ously.

The second factor is the constant elimination of the carbon-dust produced by attrition or abrasion between the granules. This dust, when permitted to accumulate settles to the bottom of the chamber forming a compactmass or cake of comparatively low resistance which is sifted out of the chamber through very small perforations O in the diaphragm, as shown more clearly in Fig. 6. The electrode E is similar to electrode E but has a somewhat larger electrode-surface and also has a beveled or rounded edge and is also of the chamber, or from the upper'electrode,

outward at the top of the mass and in reverse order at the bottom of the mass.

In practice the chamber should not be more than three-fourths filled with the granules, as indicated at F, so that they may have ample room for free movement. The sides and curved top of the chamber should be plated with gold to provide asmooth non-corrosive surface and -maintain constantly good connection with the granules. The upper or rear carbon-electrode E may be dispensed with and an adjustable plug J, correspondingly formed and plated with gold at its tip, used in'its stead. The diaphragm D is of suitable non-conducting material, for example, mica, but the diaphragm may be of a conducting substance, in which event it shouldbeinsulated from the containing case M. The diaphragm may also be of magnetic substance-and directly serve as an armature to the poles T of the receiver T. A preferred arrangement of armature is shown at T in Fig. I and further illustrated in Figs. 2, 4, 6, and 8. The armature T is of rectangular outoutline in Fig. 4;). The ends of this. armaline as viewed at its back (see the dotted.

ture are squared with the back, and the sides are beveled toward the front, and its front may be triangular, or the-front edgev may oszpor preferably mounted on the stud S with the electrode E, but 011 the opposite side ofthe diaphragm and on the opposite end of the stud S. j

To avoid injury to the transmitter in attaching and detaching the armature, an intermediate threaded nut or bur T is placed on the stud between the armature and the diaphragm to firmly clamp the diaphragm bet-ween it and the head of the stud, which latter is within the carbon-chamber. To adapt this form of beveled armature to the poles T of the receiver T, the poles are correspondingly beveled as shown in Figs. 1, 2, 4, 7, and 8. The pole pieces T are integral with the soft iron extension cores T of the receiver T, as is more clearly shown in Fig. 7. An advantage'of this form of armature and pole or pole pieces resides in the securing of a relatively extended armature movement with a very close adjustment or very small flux space or air-gap between the armature and its attracting pole or poles, without subjecting the members to actual contact. This .is illustrated in Fig. 8, where the line or mark T designates a magnetic flux line or the length of the airgap between pole and armature, and'the line or mark T designates the length or range of movement of the armature and the direction thereof. The length of the movement with the same proximity of the armature to the polar surface can be increased by making the slant or pitch ofthe bevel more abrupt. The diagonal polar surface has the added advantage of increasing the area of the opposed polar and armature surfaces and augmenting the efliciency of the magnetic circuit.

To secure the best results for an arrangement of armature and two poles, as shown, the air-gaps on both sides of the armature .should together beconsiderably less than the distance directly between the poles. lVhere this form of armature is used with one pole, the pole should be V-shaped to conform to the bevel on each side of the armature. The helices T and T of receiver T are wound on the soft iron extension cores' T to the permanent magnet T thus establishing a constant residual magnetic stress or sensitization of the vibratory armatureelectrode TE. The helices are shown (in Fig. 1) to correspond with the circuit arrangemeht designated and illustrated in one of my systems referred to, but maybe otherwise wound and variously associated with my repeater circuits as required. The terminals of the helices are brought out or connected to their respective binding-post connections T. The receiver T is mounted upon non-magnetic blocks or pedestals T and T" and is held in position by metal clamps T The non-magnetic pedestals are mounted upon the base Z, being attached thereto by screws inserted from below the base. A manually-adjustable keeper or magnetic shunting block of iron I is pivotally supported ina recess I at the top of the front non-magnetic pedestal supporting the receiver T. This keeper is pivotally con.- trolled in its position by the screw I passing out through the end .of the non-magnetic pedestal, and whenraised betweenthe limbs of the permanent magnet of receiver T will shunt more or less of the permanent flux lines, according to'its position, thus providing a simple method of regulating the residual or sensitizing magnet c influence with reference to the armature T. When the keeper is permitted to contact, as indicated by the dotted outline thereof, with the rear ends of the extension cores T the attraction of the permanent magnet for the armature T is at a minimum.

It will be appreciated by those skilled in the artthat it is very diflicult in practice, or manufacture, to secure permanent magnets of uniform strength, or to have them'of a certain desired strength and for use in an. instrument as delicately constituted as a telephonic relay. The magnets usually have an excessive strength or attractive effect on the transmitter armature, hence it is advantageous that they be provided with some means of adjustment to vary their attraction on the transmitter. This is so, for the reason, that the electro-magnetic effects on I the transmitter are very weak at best, and a surplus permanent magnet effect so overpowers them that the transmitter is affected only slightly or not at all. The permanent magnetic attraction should in each case be independently controllable so that it may be nicely proportioned to the electro-magnetic effects, to enable the armature of the transthrough the base by means of insulating tubes or bushings, as shown in Figs. 1, .2, and 4. The transmitter is pivotally supported on base Z-by the pedestal M which is bolted to the base, as shownin Fig. -2. The pedestal has two lugs or prongs M", see Fig. 3. Between the prongs is placed the, adjustable arm M provided with a forked extension, to the ends .of which is aifixed a ring M the transmitter case M* being attached thereto by screws. The adjustable arm M is also provided with an elongated aperture M, F i 5, through which, as well as through t e lugs M, a screw-bolt M passes. The elongated aperture M permits of a forward and backward adjustment of the transmitter M with its diaphragm-armature T D with reference to the poles T of receiver T.

A'set-screw M Figs. 1, 2, 3 and 5, is inserted through the rear portion of the arm M so as to protrude into the aperture'M against the screw-bolt M thus permitting a secondary adjustment and providing a stop for the armature with reference to the recciver and preventing actual contact of the armature with the magnet, hence avoiding, in the adjustment 'of'the members with relation to each other, violent stresses of the delicate diaphragm. The arm,M is held in proper place between the lugs M byythe screw-bolt M Fig. 3, said screw-bolt also extending through the two washers M and the thumb-nut M The loosening or tightening of the thumb-nut permits the arm to be moved and set in any of its desired positions. The arm M can swing around the screw-bolt pivot through anarc of more than half a circle, say 270 degrees, thuspermittingthe transmitter to be readily turned into an inverted position for .inspection and repair without disturbing the receiver or disconnecting the parts. 4

The casing M of the transmitter forms one of thetransmitter terminals for connecting the transmitter in its primary or battery circuit. This connection is made through the arm 1 the pedestal M ,'base Z and binding-post M The other terminal of the transmitter is the electrode E, to which the-flexible conductor M is connected and conducted to'the insulated binding-post M For clearness, this connection is shown (see Figs. 1 and-2) wired through the base Z and carried to the binding-post M in the manner illustrated with reference to connecting the receiver terminals. This connection should, however, be made through a flexible conductor carried'back over the supporting pedestal to permit the transmitter to be free to swing upward on its trunnion. The adj ustable plug J carrying the top or rear carbon electrode E is adapted, as a screwpiston, to regulate the resistance of the transmitter by raising and lowering the level of the carbon-granules in the chamber and also by varying the distance between the two electrodes. The diaphragm or vibrating armature-electrode DE is fastened at its periphery to the case M by the ring M, which is provided (as is also the front portion of the case) with screw-threads for the purpose.

The repeater as described ,above' can be provided with the protective casing orcover ters Patent is:

Y, shown in Figs. 2,3, and 4:, which as shown is of semi-cylindrical form having flatends. The cover is supported in position by the bead or flange Z that extends around the' while spring Z attached to the base Z and forming a catch with the projection or ear Y retains the cover in place at its upper end. The cover is provided with apertures Yat each end to permit the passage of the circuit terminals to their respective bindingposts. 4

What I claim and desire to secure by Let- 1. In a telephone repeating device, a transmitter including a case and a vibrating diaphragm united to form a. granule-containing chamber, an electrode on the diaphragm projecting into said chamber, the wall of said chamber that opposes sald diaphragm being concavedly curved and having a re-' entrant center forming an electrode, whereby free movement of granules within the chamber is promoted and packingthereof prevented.

I 2. In a telephone repeating device, a transmitter including a case and a vibrating diaphragm united to form a granule-containing chamber, an electrode on the diaphragm projecting into-said'chamber, the wall. of said chamber-that opposes said diaphragm being concavedly curved and having a rentrant center, and an adjustable electrode on said reentrant center, substantially as described; 3.- In a telephonic repeating device, in combination, a transmitter and an adjustable and oscillatory arm or support upon which the transmitter is mounted, a support for said adjustable arm, and a base to which the support is attached, whereby thetransmitter may be adjusted to its recelver.

4. In a telephone repeater relay, the combination with a base or support, of an electro-magnetic receiver and a resistance-varying transmitter, confronting each other in repeater relation, a permanent-magnet for sensitizing the receiver, and means associated therewith for regulating its effect upon the transmitter, bevel-faced poles for thereceiver, an adjustable and pivotal arm carrying the transmitter, and a single diaphragm interposed between the transmitter and the receiver, said diaphragm bearin an armature having bevel-faced polar-facing surfaces corresponding to the beveled magnet poles, substantially as shown and described.

5. In a telephone repeater relay, the com-z the normal resistance of the transmitter, an the permanent-magnetic efiect to the electroadjustableald oscillatablle support for the magnetic effect are obtained. transmitter or var in t e norma relation 1 T between the transmitter and the receiver, and NATHAL IEL WARTH' 5 independent means for varying the normal Witnesses:

attraction of the permanent-magnet upon J. WARREN MILLER, the armature whereby a regulable ratio of HOMER J. WARD. 

